Picking Master Locks

Written by Jeremy Horelick

When you consider their thousands of possible combinations, picking Master locks can seem next to impossible. But by understanding how a combination lock works, it's not too difficult to learn the techniques needed to defeat these systems. As with all security measures, Master locks are meant to be a deterrent, not an infallible protection mechanism.

The secret to picking Master locks is getting all three of their internal cams into alignment. Once this happens, a latch connecting with the rear face of your lock can successfully engage its hasp and spring the lock open. But this latch can only trigger the hasp if it's permitted to slide through all three of the cams' indentations (which happens when the correct combination is given).

Picking Master Locks, Continued

You may have seen Master locks in padlock or combination format. For the former, the techniques used in picking are essentially the same as those applied to any pin-tumbler contraption. That's because such set-ups still depend on keys to raise and lower the locks' internal pins so that they're flush with the shear.

When picking Master locks of the combination variety, locksmiths must engage all three cams so that they turn in unison, then reverse direction so that only two cams spin. Once two are in alignment, the direction is reversed a second time so that the top cam can spin independently until it too is in alignment. To do this, you don't need fancy locksmith tools such as lock pick guns and electrics. You need only have the standard lock pick, tension wrench, and the requisite patience and skill.